Combination powdered-granular catalyst hydrocarbon conversion system



June A5, 1945.' 1 M PAGE, JR 2,377,513

COMBINATION POwDERED-GRANULAR OATALYST HYDROOARBON CONVERSION SYSTEMOriginal Filed Dec. 19, 1939 34 w Pressa/z 34 l CHS S FEEfps *32'Zhler/K? )Eff Patented `lune .5, 1945 COMBINATION POWDERED GRANULAR.CATALYST HYDROCARBON CONVERSION SYSTEM James M. Page, Jr., Chicago,

"lll., assignor to Standard Oil Company, Chicago, Ill., a corporation oflIndiana Original application December` 19, 1939, serial No. 310,010.,Divided and this application December 5, 1941, Serial No. 421,760

(Cl. IBG-52) 9 Claims.

This invention relates to the catalytic converslon of hydrocarbons intohigh quality motor fuel and it pertains particularly to an improvedmethod and means f'or effecting the regeneration of powdered and`granular catalysts. This is a division of my co-pending applicationSerial No. 310,010.

There are at least three distincttypes of systems for effectingcatalytic conversion of hydrocarbons: (l) the stationary type whichcomprises a xed catalyst bed through which gases or vapors flow; (2) themoving bed type which comprises means for continuously or intermittentlyintroducing and withdrawing catalyst from a reaction chamber during thecourse of the reaction, and (3) the catalyst suspension type whereinpowdered catalyst is carried through the system suspended in the gasesor vapors undergoing treatment. Each of these systems is characterizedby certain advantages and certain disadvantages, both with respect tocost and facility of operation and with respect to yields and propertiesof products produced.

One of the chief objections to moving bed catalyst systems4 is thelargeamount of catalyst lost as fines which inevitably result from theabrasion, crushing, etc. incident to the'transfer of catalyst materialthrough the conversion chambers, strippers, regeneration systems,conveyors, etc. Since catalyst material is expensive it is essentialforcommercial success that catalyst losses lbe reduced to a minimum.

Suspended catalyst systemsl employ catalyst material of such fineparticle size that considerable diiiiculty has the catalyst fromreaction products. Furthermore, the suspended catalyst systems arenecessarily concurrent in operation and such systems therefore lack theadvantages obtainable by countercurrent flow of hydrocarbon vapors andcatalyst. An object of my invention is to provide a. combination ofmoving bed and suspended catalyst systems wherein the disadvantages ofboth systems Vwill be practically elminated and the advantages of bothsystems will be obtained. A further object of the invention is to obtaina; better productl distribution than has heretofore been obtainable incatalytic conversion systems used for the production of high qualitymotor fuel. In catalytic cracking, for instance, it has been found thatpowdered catalyst operations give a product which contains relativelylarge amounts of oleiins and relatively small amounts of aromatics.Fixed or moving bed systems, on the other hand, tend to produce beenencountered in separating more aromatics and a lesser amount ofunsaturates or olens. A high olefin content is objectionable because ofits tendency to polymerize to form gums, etc. and because of its lowsusceptibility to anti-knock agents such as lead tetraethyl. Aromatics,particularly benzol, are objectionable in certain fuels such as aviationfuels because of low total heat content. A n ob- `ject of my inventionis to produce a motor fuel of good lead tetraethyl susceptibility and ofhigh total heat content. A further object is to produce a balanced motorfuel containing large amounts of isoparains. A still further object isto obtain maximum yields of hydrocarbons in the gasoline boiling rangewith minimum losses to gas, coke, etc.

In certain reactions, particularly reforming, or aromatization, it isessential to have a relatively large caltalyst-to-oil ratio. It isdiicult, if not impossible, to obtain this desired ratio in aoncethrough powdered catalyst system because the oil vapors will notsuspend and carry through. the reactor the necessary amount of catalyst.An object of my invention is to provide a method and means forincreasing the effective catalyst-tooil ratio in the powdered catalystsystem. A further object is to provide a soaking section in a powderedcatalyst system which willv permit complete expenditure of the powderedcatalyst activity.

A further object of the invention is to provide V a unitary system foremploying both granular and powdered catalyst and for simultaneouslystripping and regenerating both powdered and granular catalyst Whilethey are associated with each other. A further object is to provide amethod and means whereby either the powdered catalyst or the granularcatalyst or both may be only partially regenerated; by leaving a smallamount of carbon on the catalyst I may effect savings in the expense ofregeneration, i. e., avoid the cost of complete regeneration and at thesame time obtain regeneratedvcatalyst of satisfactory activity for oneor both stages of the process. A i

further object is eiiectively to utilize the fine material resultingfrom attrition of granular catalyst without the necessity ofrepelleting.

A further object is to provide a catalytic conversion system ofmaximumiiexibility, i. e., one in which the character of conversion maybe varied over wide ranges depending on the amountl and type of granularand powderedcatalyst, 'respectively, and the operating conditionsemployed for these respective catalysts. For instances,vin anaromatization process the ydehydrogenation may be effected chiefly bythe preliminary contact with powdered'catalyst andthe oleiins thusproduced may be cyclicized in the moving bed system. Otherobjects Vofthe invention will bel apparent from the following detailed description.

In practicing my invention a powdered catalyst is suspended in hothydrocarbon vapors and passed concurrently therewith through a transfer;line or primary conversion zone to the base of a moving bed granularcatalyst conversion chamber. As the hot vapors together with suspendedpowdered catalyst pass upwardly through the moving granular catalyst bedthe powdered catalyst material is effectively filtered out of the gasesand vapors so that the gases leaving the upper part of the granularcatalyst conversion chamber are substantially free from catalyst.Occluded oil is then removed from the mixture of spent granular andpowdered catalysts and the spent catalysts are simultaneouslyregenerated in a closed conduit which also acts as a conveyor.

This conveyor discharges into a secondary regenerator to complete theregeneration of granular catalyst material and to complete the removalof suspended powdered catalyst therefrom. 'I'he powdered catalyst isrecovered from regeneration and stripping gases by pneumatic classifyingmeans such as a cyclone separator and after removal of regenerationgases it is reintroduced into the cycle. a Similarly, the granularcatalyst is freed from regeneration gases and returned to the top oi themoving bed conversion system.

Hydrogen may be employed in the conversion step and said hydrogen notonly serves to minimize coke deposition but serves to supply addtionalreaction heat and additional conveying means for the powdered catalyst.Any dust or fines produced by attrition or abrasion as the granularcatalyst flows through the system is recovered along with the powderedcatalyst and acts as make-up catalyst in this portion of the system.Thus catalyst losses are reduced to a minimum and onlyvery small amountsof makeup granular catalyst are required.

A preferred'` embodiment of the invention is illustrated in theaccompanying drawing which is a schematic flow diagram of my improvedcatalytic conversion system.

yThe invention is applicable to a wide variety of petroleum conversionprocesses such as cracking, isomerization, reforming, dehydrogenation,aro- Vprefer to employ catalyst material comprising a metal oxide, i.e., catalysts of the silica-alumina type or of the type wherein metaloxide is deposited on silica. Activated natural clays such as acidtreated bentonite (Super Filtrol) is an example of the so-called naturalcatalysts of the clay type. Synthetic catalysts may be prepared byco-precipitating silica gel with a metal oxide, impregnating silica gelwith mineral salts which on drying and heating are converted into imetaloxides or hydrolytically. adsorbing metal oxidesy on the silica gelsupport. The. metal oxides deposited on the silica gel or on activatedclay may be one or more oxides of such metals as aluminum, magnesium,thorium, titanium, zirconium, beryllium, cerium, copper, nickel,manganese, etc. Such catalysts and their methodsof preparation are knownto the art and need no further description.

For dehydrogenation, reforming or aromatization I prefer to employgroupVI metal oxides mounted on active alumina. About 2% to 6% molybdenumoxide on alumina or about 5% to 15% of chromium oxide on alumina arehighly satisfactory but it should be understood that oxides of tungsten,uranium, vanadium, cerium, etc, may likewise be used. The oxides may bemounted by impregnation or adsorption. Since the specific catalystsl'arid' methods of preparing them are well-known no further descriptionthereof is necessary. Bauxite or activated clays may be employed fordesulfurization or isomerization. Copper pyro-phosphate or phosphoricacid impregnated on kieselguhr may be employed -for polymerization.These and many other catalysts and catalytic mixtures are well-known tothose skilled in the art.

The catalyst in my system is used in two disl tinct forms, a granularform and a powdered matization, desulfurization, alkylation, polymermaybe dehydrogenated, polymerized, alkylated, etc. Naphthas may beisomerized, dehydrogenated, reformed, aromatized, etc. Gas oils andheavier hydrocarbons may be cracked or destructively hydrogenated and insuch reaction many of the other reactions hereinabove enumerated willalso take place. The charging stocksl may be petroleum or petroleumfractions of any kind or source or oil produced from coal, shale andother organic materials or produced by the hydrogenation of organicmaterials or produced by synthesis such for example as the carbonmonoxide-hydrogen synthesis of the so-called Fischer-Tropsch process. Inthe preferred examples I will describe the use of an East Texas gas oilfor the catalytic cracking and an East 'Iexas naphtha for the catalyticreforming, but

Generally speaking, any type of hydrocarbon charging stock may beemployed, gases form. By the term- .granular catalyst I mear/,1il

to include not only the granules or fragments of natural or syntheticorigin but I also include pellets, extruded masses and particles whichhave been preformed by any other process. The particle size in the caseof granular catalysts may vary considerably but is preferably smallerthan quarter inch and larger than mesh (although it may be as small as400 mesh) and is fairly uniform in particle size. i The powderedcatalyst, as the name implies, is of relatively small particle size, i.e.,-sufliciently small to permit suspension in a vapor stre'am ofreasonably high velocity. I prefer to employ catalyst sizes below 100mesh and even below 400 mesh but it will be understood that larger sizesmay be employed, depending somewhat upon the nature, physical form anddensity of the catalyst material itself. A feature of 'the invention isthe pneumatic classiflcation of catalyst which automatically separatesthe granular from the powdered components; powdered components which areseparated pneumatically may, 'of course, be suspended in oil vapors.

When my invention is utilized for catalytic cracking the gas oilcharging stock is introduced through line Illby pump Il, coils l2 ofpipe still I3 and thence by transfer line I4 to tubular reactor I5.Powdered catalyst from storage tank IS is introduced through line l1(which may be provided with a suitable pressure feeding mechanism) intotubular reactor l5 and it may be dispersed into the tubular reactor bymeans of steam or other gas introduced through lines I8 or I9. Thevapors and suspended catalyst material in tubular reactor I arepreferably at a temperature of about '750 to 1050 F., for example about900 F. and are at a pressure which may range from about atmospheric to200 pounds per square inch, for example about to '75 pounds per squareinch. The velocity of ow throughthe tubular reactor should be sufficientto maintain the powdered catalyst in suspension and the weight ratio ofcatalyst to oil should be about 0.5 to 15.0, for example about 2 to 2.5.'I'he time of contact in tubular reactor I about 1 to 50 seconds, but ispreferably about 10 to 25 seconds.

The gases, vapors, reaction products and suspended catalyst aredischarged at the base of moving bed granular catalyst conversionchamber 20, preferably in a space between the wall of said chamber andinverted frusto-conicalbaille 2|. Conversion chamber 20 'ismaintainedsubstantially full of granular. catalyst material whichcontinuously or intermittently moves through the conversion chamber fromtop to bottom. As the gases and vapors move upwardly `against thedownwardly moving bed of granular catalyst the powdered catalystmaterial is effectively filtered out ofthe hydrocarbon vapor stream sothat the gases, vapors and products which are removed n from the top ofthe chamber through line 22 contain no catalyst material. Frusto-conicalbaille 23 provides an open space from which vaporous products may bewithdrawn.

Conversion chamber 20 is .preferably maintained atabout the same orslightly lower temperature and pressure than tubular reactor I 5 5 mayrange from'- ber 20 while the other is discharging into stripping column33. The alternate feeders are employed because the conversion chambermay be operated at a different pressure than the stripping chamber andit is desirable that gas leakage be prevented between these twochambers. 'I'he pressure in feeders 32 and 32' maybe controlled byintroducing or withdrawing gases therefrom through lines 34 and 34'.

The spent catalyst mixture falls downwardly in stripping column 33 overinclined baffles 35 couny tercurrent to a hot inert stripping gas suchas normally gaseous hydrocarbons, ilue gas, steam, etc. introduced atthe base of the column through line 36. Column 33 is of relatively largediameter and the flow of stripping gas is sufllciently slow to avoid thecarrying away of powdered catalyst through line 31 which leads to asuitable oil recovery system (not shown). Should any powdered catalystbe carried to the oil recovery system it may be separated from the gasesor hydro- .carbons by filtration, sedimentation or any otherconventional means and returned to the system.

During the stripping step the temperature of the mixed powdered andgranular materials is preferably maintained above about 750 or 800 F. Ifthe catalyst is cooled to lower temperatures it should be reheated tothe kindling point of the carbonaceous material deposited thereon beforethe regeneration step.

Regeneration of the powdered catalystand partial regeneration of thegranular Icatalyst is effectand it should be understood that both thereactor y and the chamber should be suitably insulated or if desiredprovided with heating means. In conversion chamber 20 the gases andvapors pass through the granular catalyst at a space velocity of about0.1 to 10.0 volumes of clrrarging stock (liquid basis) per volume ofcatalyst space per hour and the catalyst holding time. i. e., -thelength of time a given particle of catalyst requires to travel throughthe conversion chamber, may vary from about 0.2 to 20.0 hours. Certainreactions which were initiated in the tubular reactor are completed inthe conversion chamber and certain products which are formed in thetubular reactor (for example, olefins) may be converted into moredesirable products (for instance aromatics) in the conversion chamber.The combination of tubular reactor and moving bed catalyst conversionsystem results in the production of hydrocarbons of high anti-knockvalue, good lead tetraethyl susceptibility, good stability againstoxidation, etc. and the combined treatment thereof -produces a gasolineof unusually v high quality.

The gases and vapors are introduced by line 22 through lines 24 and 25toa suitable fractionatingsystem 26 which is diagrammaticallyrepresented as a tower with a reflux means 21 and reboiler means 28; anyconventional system of b'ub- 'ble towers, stabilizers, etc. may beemployed' for the fractionation step. Gases are withdrawn l'overheadthrough line 29, gasolinev through line 30 and heavier productsthrough line 3 I. I

The spent catalyst mixture from the base of conversion chamberV 20 isalternately withdrawn into one of the sealed feeders 32 and 32', one ofYsaid feeders being connected to conyersion chamed in tubular conduit 38which likewise serves to convey the catalyst material from the stripperto tower 39. A hot ue gas containing small amounts, preferably about0.5% to 10% of oxygen. is introduced through line 40 by blower 4I and itserves both as a pneumatic conveying means and as a regenerating gas forthe spent catalyst. Catalyst material is forced through conduit 38 at asufficiently high velocity to carry the granular catalyst material aswell as the powdered catalyst material to tower 39 and in the course ofits flow through this conduit the powdered catalyst may be substantiallycompletely regenerated, i. e., freed from combustible carbonaceousmaterial. Additional oxygen containing gas may be introduced at spacedpoints 38a, 38h, etc. along conduit 38 which may also be supplied withcoolers 38e and 38d. The coolers may heat extraneous iluid such as air,steam, diphenyl, etc. The mixture of granular and powdered catalyst isintroduced at high velocity into the top of tower 35. The granularcatalyst then drops out of the stream and falls downwardly overVinclined bailles 42 countercurrent, if desired, to a stream ofadditional regenerating gases introduced at the base of tower 39 throughline 43. Tower 39 is relatively tall but of narrow cross section and thevelocity of gases introduced through line 43 is suiiicient to pick upany powdered catalyst and carry it out the line 44 to the top of tower45 which is provided with a suitable baille 46 for effecting theseparation of powdered catalyst from -the supporting gases. Any desiredtype of pneumatic classier may be employed for separating the powderedcatalyst from the granular catalyst material, I prefer to employ asimple baIlled device of the cyclone separator type for separatingpowdered catalyst from gases and vapors. Instead of completely.regenerating the powdered catalyst andv partially regenerating thegranular catalyst in. conduit 38 I may limit the amount of oxygenintroduced through lines 40, 38a, etc.' to effect only partialregeneration of the powdered catalyst. This expedient is particularlydesirable in the case oi -those catalysts which arev initially soextremely active as to cause a degradation of the charging stock 'whenthe powdered catalyst is reacted throughout in reactor l5. By leaving asmall amount of carbon on the powdered catalyst the initialsuper-activity may be suppressed Aand the desired conversion may beobtained in tubular reactor l5 without undueV degradation of thecharging stock to gases and coke,

Alternatively, the powdered catalyst may be substantially completelyregenerated while the granular catalyst is only partially regenerated,i. e., the granular catalyst which is separated from the powderedcatalyst may be charged directly to chamber 50 and the regenerationchamber 39 may be unnecessary. This expedient will be useful where themajor part of the conversion is effected in reactor I5 and wherein oneof the main functions of the granular catalyst `bed is to complete theconversionand to'separate the powdered catalyst from reaction products.'Powdered catalyst. falls downwardly in tower 45' over inclined baffles41 countercurrent to stripping gas which is introduced at the base ofthe tower through line 48, the amount ofstripping gas being sufcientlysmall to prevent any resuspension of the catalyst material. By the timethe catalyst reaches the base oftower 45 for discharge into catalystchamber I5 it is substantially freed from oxygen. The regeneration andstripping gases are removed from the top of tower 45 through vent lineI9. In those cases wherein the regeneration gases do not containappreciable amounts of oxygen the step oi stripping regenerated catalystmay be unnecessary.- In fact, posiclassification means and utilizedalong. with powdered catalyst. The problem of removing powdered catalystfrom reaction products has been eliminated since the powdered catalystis effectively ltered out of the vapors during their passage through themoving bed of granular catalyst. Occluded oil is removed from bothpowdered and granular catalyst in one and the same stripping tower 33and in conveyor 38 I e'ect tive advantages may be obtained by avoidingthis Y stripping step. particularly where steam, etc. is

used as a stripping agent.

Granular catalyst passes from the base of tower 59 through a suitableconduit or conveyor to the top of catalyst chamber 50. In actualpractice ftower 39 should be placed above chamber 50, although anysuitable conveying means may be employed if such arrangement is notconvenient. A stripping gas introduced through line 5I removes theoxygen-containing gases from the granular catalyst, the spent strippinggases being removed through line 52. The regeneration operation may becarried out at temperatures of 950 .to 1l00 F. but preferably not above1050 F. and preferably under pressure which serves to lower the kindlingtemperatureand reduce the possibility of overheating the catalyst. Apressure of -200 pounds per square inch is recommended.

The granular catalyst which has thus been regenerated and stripped andwhich is preferably maintained at a temperature of about 900 to 950 F.is then alternately charged toone of the feeders 53 and 53', one of saidfeeders being connected to chamber 50`whi1e the other is dischargingcatalyst material into conversion chamber 20. Pressuring gas may beapplied through lines E4 and alyst.

. and somewhat higher temperature.

regeneration of the powdered catalyst simultaneously with the partialregenerationv of granular catalyst. Regeneration o`f granular catalystis thus partially effected by concurrent flow in line 38 and partiallyby countercurrent ow in tower 39. Throughout the regeneration system thecatalyst is moved in a stream of gases which efflciently insulate eachcatalyst particle and prevent the development. of hot spots. By thissystem regeneration temperatures can be easily controlled and they arepreferably maintained below about l200 F. although withv certaincatalysts regeneration temperatures as high as 1400 F. are tolerable.'Hydrogen maybe used in the cracking step described above in a mannerdescribed below.

When the invention is applied to catalytic reforming or aromatizationthe flow will be generally similar to that hereinabove described but thereaction conditions Will be somewhat changed and will preferably includethe presence of added or recycled hydrogen. Thus insteadof a gas oil Icharge a low knock rating naphtha through line I0 and heat it to atemperature of about 800 to ll00 F.; preferably about 975 F. Hydrogenfrom storage tank 56 is introduced by compressor 5l and line 58 to coil59 in furnace I3 and thence through line I9 for assisting in thedispersion of the powdered catalyst material in tubular reactor I5. Thisreactor may be maintained at low pressures (atmospheric) in theabsenceof hydrogen but when hydrogen is .thus employed I prefer to maintain apressure of about 50 to 400 pounds per square inch, for example about200 pounds per square inch. The catalyst-to-oil ratio will be preferablyhigher than in the case of catalytic cracking and, for example, may bevabout 1:1 to \:l.

The injection ofthe hydrogen provides additional carrying means forsuspending the cat Hydrogen is preferably employed at the rate oi about1/ to 8 mols per mol of charging stock and is preferably heated vto atemperature higher than the temperature to which the naphtha is heatedin furnace I3, for `example 50 to 100 F. or more. The space velocity inreactor I5 in this case should be about 0.1 to 10.0, for example aboutl, volumes of liquid oil charged per hour per volume of actual catalystmaterial in the reactor at any instant. Space velocity is usuallydeiined as the volume of oil per volume of catalyst space per hour andin this instance the catalyst space is the space which would'be occupiedby the catalyst in the reactor at any instant if that catalyst wereallowed to comete rest and settle in the bottom of the reactor.

The reforming or aromatization conditions in chamber 20 will besubstantially the same as'for catalytic cracking except for the higherpressure The reaction products, howevenare not passed through line 24but are withdrawn through line 60, heat exchanger 6I and cooler 62 tohydrogen separator 63 which ispreferably operated at about reactionpressure andn at'a temperature of about 35 to 100 l1". Hydrogen from theseparator is passed by line `(ill to storage tank 56. Liquids from theheat exchanger 6| to line 25 and fractionating system 26. It should beunderstood, of course,

. that the hydrogen need not be pure but may contain 50% or more ofhydrocarbon gases. If hyi tent in reactor l and drogen of higher purityis desired suitable scrubbing or purification means may, of course, beemployed.

when the. invention is thus applied to reforming or aromatization it maytake place in two steps, the dehydrogenation being effected in a tubularreactor, the reaction in the tubular reactor l5 being chieydehydrogenation and the,

Y reaction in chamber 20 being chieiiy ring closure or aromatization. Inboth of the above examples I have described the use of granular andpowdered catalyst, respectively, which are of the same composition. Itshould be understood, however, that I may employ a powdered crackingcatalyst and a granular reforming catalyst in which case the chargingstock will be chiey converted into low boiling hydrocarbons of higholefin conwill then be largely converted into aromatics in conversionchamber 20. Not only may the nature of the catalysts be different in thepowdered and granular systems, respectively, but the relative amounts ofthe catalyst employed, i. e., catalyst-to-oil ratios, space velocity,etc. may be varied throughout relatively wide ranges as hereinabovenoted. In fact, the granular material may be non-catalytic, may simplyfunction as a' lter for removing powfrom gases. The removal of catalystfines from a gaseous stream by means of a moving bed of granularmaterial is an important feature of the invention, and it may beemployed for removing the lines, for instance, in the gases leaving thesystem through line 49 as well as in conversion reactor 20.,

My invention provides an extremely exible catalytic conversion systemwhich can readily be adapted to the conversion of almost any widelyvarying charging stocks into high quality motor fuel. vWhile I havedescribed preferred embodithe above disclosure.

I claim:

1. In a process for catalytically converting hydrocarbons into motorfuel by the use of a mixture of powdered and granular catalystmaterials, the method of regenerating spent catalyst which comprisessuspending said spent catalyst mixture in oxygen-containing regenerationgas at a tem, `Derature of at least750 F. and pneumatically conveyingsaid suspended mixture through a regeneration zone while simultaneouslyregenerating powdered catalyst and partially regenerating granularcatalyst,` separating regenerated powdered catalyst from the partiallyregenerated granular catalyst, further regenerating the separatedgranular catalyst and stripping regeneration gases from the regeneratedpowdered catalyst Vand regenerated granular catalyst, respectively.

effecting catalytic conversion use of both grammar and powdered catalystmaterial which process comprises introducing granular catalyst at thetop of a substan-l .sion zone, passing said stream upwardly in saidconversion zone whereby the powdered catalyst removed from said streamby said bed of granular catalyst, removing reaction products from theupper part of said conversion zone, stripping the mixture of granularand powdered catalyst removed from the base of said conversion zone,suspending the stripped catalyst in oxygen-containing regeneration gas,conveying said catalyst to a high level by means of said regenerationgas while eiiecting at least partial regeneration of said catalysts,separating powdered catalyst from-granular catalyst at said highelevation, effecting further regeneration of granular catalyst after itsseparation from powdered catalyst, returning said further regeneratedgranular catalyst to the top of said conversion zone, suspendingseparated powdered catalyst in a gasiiorm charging stock stream andpassing said lasty named suspension through a preliminary coriversionzone before introducing it at said low point in said first-namedconversion Zone.

4. In a. process for cataiytically converting hydrocarbons into motorfuel by the use of a mixture of powdered and granular materials, themethod of regenerating spent catalyst which comprises suspending saidspent catalyst mixture in oxygen-containing regeneration gas a1; atemperature of at least 7bu conveying Said suspended generation zonewhile simultaneously enacting partial regeneration of both powdered andgranular catalyst. separating the partially regenerated powderedcatalyst rrom the partially regenerated granular catalyst and returningat .least one of said partially regenerated catalysts to the ation ofthe granular catalyst.

17. In a hydrocarbon conversion system wherein powdered catalystmaterial comprising a metal therefrom, the method of removing catalystnes from -a gaseous stream in which said catalyst lines are suspended,which method comprises introducing a gaseous stream catalyst nes into abed of granular material whereby the granular material acts as a ilterfor F. and pneumaticaliy mixture through a. re-

regenerating the lgranular catalystA and regenerrecovering powderedcatalyst iines from said gaseous stream, removing granular materialtogether with accumulated catalyst nes from the 'gaseous stream,separating catalyst fines from the removed granular material by means ofanother gaseous streamand returning the granular material'from whichcatalyst fines have been separated into contact with the first-namedgaseous stream forthe recovery of additional catalyst flnes. Y

8. The method of claim 7 wherein the gaseous stream containing catalystnes is continuously introduced into a moving' bed of granular material,wherein granular material and catalyst fines are continuouslyremoved-from the bottom of said moving bed and continuously suspended inanother gaseous stream, wherein the catalyst finesv are continuouslyremoved from the granular material and wherein the granular materialwhich is free from catalyst ines is continuously added to the top ofsaid moving bed.

9. The method of regenerating a mixture of` powdered and granularcatalyst material which has been coated with carbonaceous deposits.which method comprises suspending a mixture of coated powdered andgranular catalyst may terial in an oxygen-containing gas and burningcarbonaceous deposits fromsaid material in a. primary combustion zonewhile it is in gaseous suspension, introducing the suspended materialfrom the primary combustion zone into a secondary .combustion zone,removing powdered material together with a gaseous stream from the topof said secondary combustion zone and removing granular catalystmaterial from a low point in said secondary combustion zone.

JAMES M. PAGE, Jn.

